Fire Safety Science Digital Archive

In flames produced by freely burning fuel, buoyancy may play an important role in determining the speed of the gases in the flame zone and hence the flame height. Measurements have been made of the height of flames from burning cribs of wood on a square horizontal base and a few for two other arrangements. The results are consistent with a dimensionless analysis, leading, for one particular fuel system, to the functional equation L/D = (L/J)(Q^2/(gD^5)), where L is the flame In flames produced by freely burnang fuel, buoyancy may play· an important role in determining the speed of the gases in the flame zone and hance the flame height, D the linear dimension of the fire or orifice, Q the volumetric flow rate of gaseous fuel at ambient temperature and g the acceleration due to gravity. In turbulent fuel jets L/D is a constant for a given fuel which is shown theoretically to be a limiting case of this relationship.